MRI: Acquisition of equipment for an integrated gas analysis and labeling radiocarbon system with a focus on Arctic carbon and geochronology

该奖项支持北亚利桑那大学收购放射性碳系统。该系统将被用来研究碳循环的现代变化和过去的气候变化。放射性碳(碳-14或碳14C)是碳的一种同位素，有六个质子和电子，另外还有两个中子。由于额外的中子导致持续不断的放射性衰变，放射性碳起到了时钟的作用。放射性碳测年是最广泛使用的科学工具，用于确定事件的时间和几万年前地球、环境和人类过程的变化速度。这笔赠款支持购买仪器来完成气体和放射性碳标签系统，这将使调查人员能够对北极的环境问题获得新的见解。这些仪器将与促进培训科学家将放射性碳应用于生态学和地球系统科学的教育活动结合起来。认识到变革性研究的巨大潜力，北亚利桑那大学(NAU)最近与IonPlus签订了购买迷你加速器质谱仪(迷你碳测年系统；MICADAS)的合同。该奖项用于购买气体和标记放射性碳系统，包括气体离子源(GIS)和自动石墨设备(AGE)，前者是快速分析二氧化碳气体形式的极小样品所必需的，后者结合了样品燃烧、提纯和石墨化步骤，将用于从低水平标记实验中分离样品并完成综合分析设施。拟议的仪器将把放射性碳的新的和发展的应用与地球和环境科学中的重大挑战联系起来，特别是在北极。放射性碳为跟踪永久冻土碳库的变化、了解北极气候系统的反馈以及了解过去的气候变化提供了独特而灵敏的指纹。测量放射性碳的技术突破和北大西洋公约组织的科学专门知识将促进对这些问题的新见解。NAU PIs将与广泛的合作者一起探索两个主要的理解主题(1)北极气候的过去变化，和(2)可能对未来气候反馈的北极碳的现代变化。除了这一以北极为重点的主题外，该仪器还将促进正在进行的广泛科学领域的研究，包括土壤碳动力学、植物和微生物生态学、火灾历史、地质灾害、考古学、历史生态学和保护古生物学。这项仪器采购将与教育和知识转让活动结合起来，以促进培训科学家将放射性碳应用于生态学和地球系统科学。这笔赠款中的综合放射性碳系统所代表的技术进步可以帮助推广放射性碳的使用，增加应用的种类和制备样品的选择，并降低成本。这需要扩大受过教育的用户群体，这将通过一个面向全国研究生和博士后研究人员的短期课程--生态和地球系统科学中的放射性碳--来产生。此外，NAU还坚定地致力于为亚利桑那州的农村地区服务，包括美洲原住民和西班牙裔人口。将利用现有的项目来吸引这些学生，提供实验室参观、演示和在实验室工作的机会。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award supports the acquisition of a radiocarbon system at Northern Arizona University. This system will be used to study modern changes in the carbon cycle and past changes in climate. Radiocarbon (Carbon-14 or 14C) is an isotope of carbon, with six protons and electrons, with two additional neutrons. Radiocarbon acts as a clock due to the constant radioactive decay that occurs as a result of the extra neutrons. Radiocarbon dating is the most widely used scientific tool for determining the timing of events and the rates of changes of Earth, environment and human processes extending back tens of thousands of years. This grant supports purchase of instruments to complete a gas and labeling radiocarbon system that will allow the investigators to gain novel insights into environmental issues in the Arctic. These instruments will be integrated with educational activities that promote training scientists in the application of radiocarbon to ecology and Earth system science.Recognizing the outstanding potential for transformative research, Northern Arizona University (NAU) recently contracted IonPlus for the purchase of a mini accelerator mass spectrometer (Mini Carbon Dating System; MICADAS). This award funds the acquisition of a gas and labeling radiocarbon system including a gas ion source (GIS), which is needed for rapid analysis of very small samples in CO2 gas form, and automated graphite equipment (AGE), which combines sample combustion, purification, and graphitization steps and will be used to isolate samples from low-level labeling experiments and complete an integrated analytical facility. The proposed instrumentation will link novel and developmental applications of radiocarbon to grand challenges in Earth and environmental sciences, with a particular focus on the Arctic. Radiocarbon provides a unique and sensitive fingerprint for tracking changes in the permafrost carbon pool, for understanding feedbacks in the Arctic climate system, and for understanding past climate change. Technological breakthroughs for measuring radiocarbon and the scientific expertise at NAU together are poised to catalyze novel insight into these issues. The NAU PIs, along with a broad suite of collaborators, will explore two major themes of understanding (1) past changes in Arctic climate, and (2) modern changes in Arctic carbon that may feedback to future climate. In addition to this Arctic-focused theme, the instrumentation will facilitate ongoing research across a broad range of sciences including soil carbon dynamics, plant and microbial ecology, fire history, geologic hazards, archaeology, historical ecology and conservation paleobiology. This instrument acquisition will be integrated with educational and knowledge transfer activities that promote training scientists in the application of radiocarbon to ecology and Earth system science. Technological advances such as represented by the integrated radiocarbon system in this grant could help spread the use of radiocarbon, with increases in the variety of applications and in options for preparing samples, and decreases in cost. This requires an expanding pool of educated users, which will be generated by a short course, Radiocarbon in Ecology and Earth System Science, open to graduate students and postdoctoral researchers nationwide. In addition, NAU has a strong commitment to serving rural Arizona, including Native American and Hispanic populations. Existing programs will be leveraged to engage these students, providing lab tours, demonstrations, and opportunities to work in the lab.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.